Table of estimated effect sizes for impact analysis studies
| Author, year CPR name | Study design (n) | Sample size calculation reported (n) | Primary outcome | Effect size: crude OR of improvement in primary outcome in intervention vs control (95% CI) | Absolute risk reductions (95% CI) |
|---|---|---|---|---|---|
| Auleley, 199715 Ottawa ankle rule | Cluster RCT (4980) | Yes (900) | Physician behaviour: referral for radiography (ankle/foot) | Crude OR 0.03 (0.01 to 0.06) | 22.8% (20.0% to 25.7%) |
| Stiell, 199416 Ottawa ankle rule | Controlled before–after (2342) | NA | Physician behaviour: referral for radiography (ankle/foot) | Ankle X-ray: crude OR 0.11 (0.08 to 0.16) Foot X-ray: crude OR 0.73 (0.57 to 0.94) | 33.4% (28.9% to 37.9%) 6.6% (1.1% to 11.7%) |
| Cameron, 199919 Ottawa ankle rule | Controlled before–after (1648) | NA | Physician behaviour: referral for ankle X-ray | Crude OR 0.96 (0.60 to 1.55) | 0.8% (−8.5% to 9.8%) |
| Boutis, 201320 Low-risk ankle rule | ITS (2151) | NA | Physician behaviour: referral for ankle X-ray | NA | NA |
| Stiell, 199717 Ottawa knee rule | Controlled before–after (3907) | NA | Physician behaviour: referral for knee radiography | Crude OR 0.42 (0.35 to 0.51) | 18.8% (14.7% to 22.9%) |
| Stiell, 200918 Canadian C-spine rule | Cluster RCT (11 824) | Yes (9600) | Physician behaviour: diagnostic imaging rate of cervical spine | Crude OR 0.82 (0.74 to 0.90) | 5% (2.5% to 7.5%) |
| Pozen, 198421 Pozen score for chest pain | ITS (2320) | NA | Physician behaviour: appropriate admission | NA | NA |
| Kline, 200922 Kline chest pain CPR | RCT (369) | Yes (400) | Physician behaviour: admission with no significant cardiovascular diagnosis | Crude OR 0.47 (0.22 to 1.04) | 5.4% (−0.2% to 10.9%) |
| Persell, 201227 Framingham risk score | Cluster RCT (425) | Yes (406) | Patient: proportion of patients with a reduction in LDL-cholesterol level by 30 mg/dL | Crude OR 0.99 (0.55 to 1.81) | 0.1% (−0.0% to 0.0%) |
| Grover, 2007 and 200825 26 Framingham risk score | RCT (3053) | Yes (3000) |
| Reduction in LDL-cholesterol level: mean difference −0.33 mg/dL (−0.5.4 to −1.1; p=0.02) | NA |
| Hall, 200323 New Zealand cardiovascular risk score | Pilot RCT (323) | NA | Physician behaviour: prescription of risk modifying drugs, management of CVD risk factors | Diabetes treatment: crude OR 1.28 (0.82 to 2.01) Antihypertensive drugs: crude OR 1.62 (0.84 to 3.12) Lipid lowering drugs: crude OR 1.48 (0.72 to 3.04) Referral to dietician: crude OR 0.78 (0.40 to 1.54) | −6.0% (−16.6% to 4.7%) −5.5% (−12.9% to 1.9%) −3.7% (−10.3% to 3.0%) 2.5% (−4.47% to 9.57%) |
| Hanon, 200024 Framingham risk score | RCT (1243) | No | Patient and physician behaviour: BP, patients prescribed dual therapy | Normal BP: crude OR 1.09 (0.87 to 1.38) Dual therapy: crude OR 0.82 (0.65 to 1.02) | −2.1% (−7.4% to 3.3%) 4.9% (−0.6% to 10.4%) |
| McIsaac, 200229 McIsaac | RCT (621 patients, 97 physicians) | Yes (850 patients, 85 physicians) | Physician behaviour: unnecessary antibiotic prescriptions (negative throat swab) | Crude OR 0.71 (0.47 to 1.08) | 4.9% (−1.1% to 10.9%) |
| McIsaac, 199828 Centor | RCT (396) | Yes (800) | Physician behaviour: antibiotic prescription | Crude OR 0.69 (0.45 to 1.05) | 8.1% (−1.0% to 17.3%) |
| McGinn, 201332 (1) Walsh rule (streptococcal pharyngitis) (2) Heckerling rule (pneumonia) | RCT (168) | No | Physician behaviour: change in antibiotic prescription | Crude OR 0.66 (0.50 to 0.86) | 9.3% (3.2% to 15.3%) |
| Worrall, 200730 Modified Centor score | RCT (533) | Yes (196) | Physician behaviour: prescribing rate of antibiotics | Crude OR 0.89 (0.57 to 1.40) | 2.9% (−8.2% to 13.9%) |
| Little, 201331 FeverPAIN | RCT (6131) | Yes (909) | Patient behaviour: patient-reported symptom severity | Adjusted mean difference−0.33 (−0.64 to −0.02; p=0.04) | NA |
| Stiell, 201033 CT head rule | Cluster RCT (4531) | Yes (4800) | Physician behaviour: proportion of patients referred for CT imaging | Crude OR 0.81 (0.69 to 0.96) | 4.7% (1.0% to 8.4%) |
CPR, clinical prediction rule.